This article explores two separate traditions that educational psychologists (EPs) in the UK have for working with systems. One of these is "systems work" with organisations such as schools. The other is "systemic thinking" for working with families. Over the years these two traditions, systems work and systemic thinking, have become crossed and intertwined. This article clarifies the connections between them by providing a historical overview, largely based on articles published by "Educational Psychology in Practice" and the thinking of R. Dallos and R. Draper on Family Therapy, of how they have developed. Opportunities for EPs working in Children Services to use systemic thinking and systems work are highlighted.